Combustion-accelerator for boiler-furnaces.



G. W. W-YMAN.

COMBUSTION ACCELERATOR FOR BOILER FURNACES.

APPL'CATION FILED JUNE 26.1912.

1 ,271,983. Patented July 9, 1918;

GEORGE W. WYMAN, or DELMAR, DELAWARE.

COMBUSTION-ACCELERATOR FOR BOILER-FURNACES.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed June 26, 1917. Serial No. 177,073.

To all whom it may concern:

Be it known that I, GEORGE W. WVYMAN, a citizen of the United States, residing at Delmar, in the. county of Sussex and State of Delaware, have invented a certain new and useful Improvement in Combustion- Accelerators for Boiler-Furnaces, of which the following is a specification. I

The invention relates to devices for supplying preheated air to boiler furnaces as an aid to combustion and consequently preventing the escape of unconsumed carbon in the form of smoke.

The principal object of the invention is to provide an apparatus by which the air thus supplied may be economically raised to the high temperature required to insure the combination of oxygen with the hot carbon gases in the furnace, necessary for complete combustion, thus increasing the efliciency of the boiler and eliminating smoke.

Another important object is to provide means for preheating the air by the hot products of combustion during their traverse of the boiler Without detracting appreciably from the efficiency of the latter by such transfer-of heat, and a further object is to so locate the preheating portion of the apparatus in such relation to the furnace and boiler as to permit the air to be heated approximately to any desired degree between the tempera ture of the gases in the furnace and thatof the gases escaping through the smoke-box,

uptake, or stack.

Another important object is to provide 7 means for inducing a flow of air through the apparatus at a velocity sufficiently high to insure the desired additional supply of oxygen to the furnace While retaining such air in the preheating portion of the apparatus for a period of suflicient length to insure the required high temperature.

The invention consists in certain novel features, and details of construction and arrangement by which the above objects are attained, to be hereinafter described and claimed.

The accompanying drawings form a part of this specification and show the invention applied to a locomotive.

Figure 1 is a side elevation of a locomotive equipped with the invention.

Fig. 2 is a vertical transverse section through the smokebox, showing the apparatus in front elevation.

The remaining figures are on "a larger scale.

Fig. 3 is a vertical transverse section through a header located in the smokebox, and its connections leading to the preheater and furnace.

Fig. .4: is a corresponding longitudinal section taken on the line 44 in Fig. 3.

Fig. 5 is a longitudinal section of a specially constructed boiler tube containing the preheating portion of the apparatus. The latter is shown in elevation therein.

Fig. 6 is a transverse section corresponding to Fig. 5.

Similar letters of reference indicate the same parts in all the figures.

A is the boiler of a locomotive, B the furnace, and C the smokebox. A A are the usual boiler flues and D D are similar flues, or heater tubes, of much greater diameter, shown as located in a line near the bottom of the boiler- These tubes D D are preferably contracted near their junction with the furnace, as indicated at D to prevent the entrance of large obstructions from the furnace.

In the upper portion of the smokebox is located a casing or header E divided by a deck or partition, E into two chambers e and 6 see Figs. 3 and 4., The upper chamber 6 receives air through a funnel F mounted on the exterior of the boiler front-end with its mouth presented forwardly and adapted to force air downwardly into the chamber 0 under a pressure induced by the forward movement of the locomotive.

Pipes G G lead downwardly in the smokebox from the chamber 6 to a heater in the form of a coil or group of pipes joined by return-bends, extending longitudinally in a portion of each of the large tubes D D, bathed in the hot gases passing through such tubes, and G Gr are pipes leading the air thus heated in the coils G upwardly into the chamber 6 of the header E. The tubes D are enlarged, as seen in Figs. 1 and 5, and constitute fines for the products of combustion and within these enlarged tubes the members G, are arranged as shown.

From the ends of the header the hot air in the chamber 6 passes through delivery conduits H H, extending to the exterior of the smokebox on each side and thence rearwardly to the furnace B. Two such conduits are shown on each side of the locomotive, delivering air preheated in the coils G G to the furnace at two separated points above the grate, as indicated at B B The inrush of air through the funnel F aided by the partial vacuum obtaining in the furnace by reason of the draft, causes avrapid-circulation through the apparatus and delivers the quantity of air required at a sufliciently high temperature to insure perfect combustion, resulting in. a corresponding economy of fuel and the elimination of smoke.

By installing the coils or heater G inthe large tubes D bathed in the hot products of combustion traversing the latter, the air to be preheated is raised in temperature Without appreciable loss, or cooling effect on the boiler, for the reason that the space between the heater and interior wall of the tube permits an uninterrupted flow of hot gases, and by varying the length of the runs or convolutions of the coils and locating them farther forward or rearward in the tubes D D, as determined by experiment, air at'any desired temperature within the heat limits of the gases at the opposite ends of the tubes may be delivered to the furnace.

It is found by experimental tests that air at 1600F., added in sufficient volume to the locomotive furnace will produce the practicallycomplete combustion desired; and also that the furnace temperature is normally about 269 F., and the smokebox temperature about 750 E, which therefore are approximately the temperatures at the rear and forward ends of the tubes; it is evident that by properly locating the heaters in such tubes, with allowances for reductions in temperature due to the cooling of the gases in the tubes, transmission through the smoke-box,

header, and delivery conduits, the air may be delivered to the furnace at a predetermined and practically uniform temperature.

Another advantage of locating the heaters in the tubes D D is that as the temperatures obtained therein are known, the coils or heaters may be so constructed as to materials and design as to resist successfully the highest temperatures towhich such location subjects them, and failure due to softening or burning out is avoided.

By locating the header and its connections in the smoke-box the temperature of the latter is the lowest to which these portions of the apparatus are subject and extreme low temperaturesare thus avoided.

The number and location of the delivery conduits H H, and large tubes D D may be varied, and other modifications made in the forms and proportions of the several parts of the apparatus.

Although the invention is shown and described as applied to a locomotive boiler it Will be understood it may be applied to stationary and marine boilers of types to which it is adaptable.

I claim:'

1. In a boiler having a furnace, fiues and smoke-box, enlarged tubes for the products of combustion in the lower portion of the boiler, a heater installed in said tubes and disposed in the path ofthe hot products of combustion, a header located .in the upper portion of the smoke-box, means dividing said header into separate chambers, means for conducting air into one of said chambers, means leading from said chamber to the heater, pipes for leading the heated air from said heater into the other chamber of said header and means leading from the lastnamed chamber to the furnace.

2. In a boiler having a furnace, 'fiues and smoke-box, enlarged tubes for the products of combustion in the lower portion of the boiler, a heater installed in said tubes and disposed in the path of the hot products of combustion, a header located in the upper portion of the smoke-box, means dividing said header into separate chambers, means for conducting air into one of said chambers, means leading from said chamber to the heater, pipes for leading the heated air from said heater into the other chamber of said header, and delivery conduits extending from said last-named chamber to the exterior of the smoke-box on each side and thence rearwardly to the furnace.

3. The combination with a furnace, its smoke-box and fiues, of enlarged tubes for the products of combustion contracted near their junction with the furnace to serve as fiues from the furnace to the smoke-box, a header located in the upper portion of the smoke-box, means dividing said header into upper and lower chambers, means for conducting air into one of said chambers, heater coils in said enlarged tubes, delivery conduits connected With said header and extended to the furnace, and means connecting each of said heater coils with each of said chambers and the connection of said conduits with said header being at opposite sides thereof.

In testimony that I claim the invention above set forth Iaflix my signature.

' GEORGE w. W MAN.

Copies of this patent may be obtained. for five cents each, by addressing the -Com1nissioner of Patents,

' Washington, D. G.

It is hereby certified chat in Letters Patent No. 1,271,983, granted July 9, 1918, upon the application of George W. Wyman, of Delmar, Delaware, for an improvement in Combustion-Accelerators for Boiler-Furnaces, an error appears in the printed specification requiring correction as follows: Page 2, line 34, for the numerals and degree-mark 269 read 2600?; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of October, A. D., 1918.

[SEAL] R. F. WHITEHEAD,

Acting Commissioner of Patents. Cl. 1 lO-57:, 

